Determination of Nanostructural Changes by Severely Plastically Deformed Oxide Dispersion Strengthened Copper Alloy

N. Romčević, M. Kos, I. Anžel, R. Rudolf, M. Gilić, M. Romčević, M. Petrović Damjanović, U. Ralević, B. Hadžić
Institute of Physics, RS

Keywords: Cu-Al nanostructured composite, ECAP process, AFM, Raman spectroscopy

Summary:

Our research work deals with the problem of producing the complex metal-ceramic nanostructural composite using the processes of internal oxidation and severe plastic deformation. For this purpose, Cu-Al alloy with 0.4 wt.% of Al was used. The internal oxidation (IO) of the sample serves in the first step of the processing as a means for attaining a fine dispersion of nano-sized oxide particles in the metal matrix. The production technology continues with repeated application of severe plastic deformation (SPD) of the resulting metal-matrix composite to produce the bulk nano-scaled structural material. SPD was carried out with equal channel angular pressing (ECAP), which allowed that the material could be subjected to an intense plastic strain through simple shear. We measured micro-hardness, AFM and Raman spectroscopy in the sample of Cu-0,4%wt. of Al before and after SDP and ECAP. The results reflect structural changes completely. Rate of hardening in the oxidation zone is lower than in the primary alloy. AFM pictures starts with a flat surface (undeformed samples), without registered Raman peaks and ends with clear wavy structures with strong Raman modes. The intensity and frequency of the structure depends on the type of sample and the degree of deformation.